> Ha ha! I originally thought the idea of throwing sour-whey
> onto the fire was so ridiculous that it couldn’t possibly
> be right (they would be more likely to pee on it than
> waste their whey ) and ended up inventing even more
> ridiculous explanations, thus ending up with whey (if not
> egg) on my face !

Apparently they’d have had plenty of it. According to

<https://nannarognvaldar.com/a-little-food-history/>,

they commonly used fermented whey for preservation.

When ancient farmsteads are excavated, remains of several
huge barrels are usually found dug down into the kitchen
or larder floor. These barrels will have been filled with
soured or fermented whey, sýra, which in Iceland was
usually a byproduct of skyr-making.

Fermented whey is an excellent preservation agent; I have
myself, as a child, eaten blood pudding and other food
that had been kept in sýra for well over a year, in an
unheated (and unrefrigerated) room. The fact is that
fermented whey not only preserves the food and its
nutrients remarkably well, it can even add to the
nutritional value of it since vitamins from the whey seep
into the preserved food. It also tenderizes and softens
the meat and gradually softens and dissolves bones. Fish
and cattle bones were sometimes kept in the fermented whey
until they had softened and then they were boiled and
eaten, although they seem to have been a rather unpopular
dinner.

Food that is kept in fermented whey for some time will
gradually acquire an increasingly sour taste. It is
sometimes said that all food will eventually taste the
same if it is kept in whey for long. Food that was
preserved in this manner was usually boiled and cooled
before being submerged in the whey. A lid was then placed
on top and if the barrel was to be kept undisturbed for
some time, some tallow was usually melted and poured over
the rim to seal it.

Fermented whey was not just used to preserve food. It was
used to flavor soups and porridges, and possibly to
marinate meat, but it was mainly used as a beverage. The
use of fermented whey as a refreshing drink was not
unknown in Norway, but it became so prominent in Iceland
that 12th century Norwegians remarked upon it. The main
reason for this is of course the lack of beer and ale.
Some beer was brewed in Iceland in the Middle Ages but
after barley cultivation disappeared completely, sýra
became the local substitute. It is not alcoholic but it
can be very refreshing and tasty for those who have
acquired a palate for it. It used to be said that two-year
old whey was fully developed. By then, it was so sour that
it was usually diluted generously with water, sometimes 1
part sýra to 11 parts water.

The whole article is very interesting.

(The title of the blog, <Konan sem kyndir ofninn sinn>, is
‘The woman who lights her oven’, if I’m not mistaken. Lots
of recipes in Icelandic.)

Brian